Bacillus subtilis 168 is the only bacterium-based host serving for the cloning of giant DNA above 1.000 kbp. As rapid verification of the genome structure is crucial during the cloning process, six of 18-base sequence recognized by endonuclease I-SceI were sequentially created in the B. subtilis 168 genome. The established method and materials should be of use for other B. subtilis derivatives.
